I'm not sure if the code above compiles and works, it's just a demonstration of what I'm doing. Okay, so...

It plays an A, but it's all choppy as if I'm not fully filling up the audio buffer. But clearly it says "play_audio_stream( BUFFER_SIZE... )" and "for ( i = 0; i < BUFFER_SIZE; i++ )" note usage of BUFFER_SIZE.